1. Technical Field of the Invention
The present invention relates to a plate thickness reduction press apparatus that transfers and reduces a slab, and the methods concerned with its use.
2. Prior Art
1. FIG. 1 shows an example of a roughing mill used for hot rolling, and the roughing mill is provided with work rolls 2a, 2b arranged vertically opposite each other on opposite sides of a transfer line S that transfers a slab-like material 1 to be shaped, substantially horizontally, and backup rolls 3a, 3b contacting the work rolls 2a, 2b on the side opposite to the transfer line.
In the above-mentioned roughing mill, the work roll 2a above the transfer line S is rotated counterclockwise, and the work roll 2b underneath the transfer line S is rotated clockwise, so that the material 1 to be shaped is caught between both work rolls 2a, 2b, and by pressing the upper backup roll 3a downwards, the material 1 to be shaped is moved from the upstream A side of the transfer line to the downstream B side of the line, and the material 1 to be shaped is pressed and formed in the direction of the thickness of the slab. However, unless the nip angle xcex8 of the material 1 to be shaped as it enters into the work rolls 2a, 2b is less than about 17xc2x0, slipping will occur between the upper and lower surfaces of the material 1 to be shaped and the outer surfaces of both work rolls 2a, 2b, and the work rolls 2a, 2b will no longer be able to grip and reduce the material 1 to be shaped.
More explicitly, when the diameter D of the work rolls 2a, 2b is 1,200 mm, the reduction xcex94t of a single rolling pass is about 50 mm according to the above-mentioned nip angle xcex8 condition for the work rolls 2a, 2b, so when a material 1 to be shaped with a thickness T0 of 250 mm is rolled, the thickness T1 of the slab after being reduced and formed by a roughing mill becomes about 200 mm.
According to the prior art, therefore, the material 1 to be shaped is rolled in a reversing mill, in which the material is moved backwards and forwards while gradually reducing the thickness of the plate, and when the thickness of the material 1 to be shaped is reduced to about 90 mm, the material 1 is sent to a finishing mill.
Another system for reducing and forming the material 1 to be shaped according to the prior art is shown in FIG. 2; dies 14a, 14b with profiles like the plane shape of dies for a stentering press machine are positioned opposite each other above and below a transfer line S, and both dies 14a, 14b are made to approach each other and separate from each other in the direction orthogonal to the direction of movement of the material 1 using reciprocating means such as hydraulic cylinders, in synchronism with the transfer of the material 1, while reducing and forming the material 1 to be shaped in the direction of the thickness of the plate.
The dies 14a, 14b are constructed with flat forming surfaces 19a, 19b gradually sloping from the upstream A side of the transfer line towards the downstream B side of the line, and flat forming surfaces 19c, 19d that continue from the aforementioned forming surfaces 19a, 19b in a direction parallel to and on opposite sides of the transfer line S.
The width of the dies 14a, 14b is set according to the plate width (about 2,000 mm or more) of the material 1 to be shaped.
However, when the material 1 to be shaped is rolled with the reversing method using the roughing mill shown in FIG. 1, space is required at each of the upstream A and downstream B ends of the transfer line S of the roughing mill, for pulling out the material 1 to be shaped as it comes out of the roughing mill, so the equipment must be long and large.
When the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b shown in FIG. 2, the areas of the forming surfaces 19a, 19b, 19c and 19d in contact with the material 1 to be shaped are much longer than those of the dies of a stentering press machine, and the contact areas increase as the dies 14a, 14b approach the transfer line S, so that a large load must be applied to each of the dies 14a, 14b, during reduction.
Furthermore, the power transmission members such as the eccentric shafts and rods for moving the dies 14a, 14b, the housing, etc. must be strong enough to withstand the above reducing loads, so each of these members and the housing must be made large in size.
Moreover, when the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b, some of the material 1 is forced backwards towards the upstream A side on the transfer line depending on the shape and the stroke of the dies 14a, 14b, therefore, it becomes difficult to transfer the material 1 to be shaped to the downstream B side of the transfer line.
When the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b shown in FIG. 2, the height of the lower surface of the material 1 after being reduced by the dies 14a, 14b is higher than the height of the lower surface of the material 1 immediately before being reduced by the dies, by an amount corresponding to the reduction in thickness.
Consequently, the leading end of the material 1 to be shaped tends to droop downwards, therefore the table rollers (not illustrated) installed on the downstream B side of the transfer line, to support the material 1 being shaped, may catch the leading end of the material 1, possibly resulting in damage to both the table rollers and the material 1 being shaped.
Recently, the flying-sizing press machine shown in FIG. 3 has been proposed.
This flying-sizing press machine is provided with a housing 4 erected on a transfer line S so as to allow movement of a material 1 to be shaped, an upper shaft box 6a and a lower shaft box 6b housed in window portions 5 of the housing 4 opposite each other on opposite sides of the transfer line S, upper and lower rotating shafts 7a, 7b extending substantially horizontally in the direction orthogonal to the transfer line S and supported by the upper shaft box 6a or the lower shaft box 6b by bearings (not illustrated) on the non-eccentric portions, rods 9a, 9b located above and below the transfer line S, respectively, connected to eccentric portions of the rotating shafts 7a, 7b through bearings 8a, 8b at the end portions thereof, rod support boxes 11a, 11b connected to intermediate portions of the upper and lower rods 9a, 9b by bearings 10a, 10b with spherical surfaces and housed in the window portions 5 of the housing 4 and free to slide vertically, die holders 13a, 13b connected to the top portions of the rods 9a, 9b through bearings 12a, 12b with spherical surfaces, dies 14a, 14b mounted on the die holders 13a, 13b, and hydraulic cylinders 15a, 15b whose cylinder units are connected to intermediate locations along the length of the rods 9a, 9b by means of bearings and the tips of the piston rods are connected to the die holders 13a, 13b through bearings.
The rotating shafts 7a, 7b are connected to the output shaft (not illustrated) of a motor through a universal coupling and a speed reduction gear, and when the motor is operated, the upper and lower dies 14a, 14b approach towards and move away from the transfer line S in synchronism with the transfer operation.
The dies 14a, 14b are provided with flat forming surfaces 16a, 16b gradually sloping from the upstream A side of the transfer line towards the downstream B side of the transfer line so as to approach the transfer line S, and other flat forming surfaces 17a, 17b continuing from the aforementioned forming surfaces 16a, 16b in a direction parallel to the transfer line S. The width of the dies 14a, 14b is determined by the plate width (about 2,000 mm or more) of the material 1 to be shaped.
A position adjusting screw 18 is provided at the top of the housing 4, to enable the upper shaft box 6a to be moved towards or away from the transfer line S, and by rotating the position adjusting screw 18 about its axis, the die 14a can be raised and lowered through the rotating shaft 7a, rod 9a, and the die holder 13a. 
When the material 1 to be shaped is reduced and formed in the direction of the plate thickness using the flying-sizing press machine shown in FIG. 3, the position adjusting screw 18 is rotated appropriately to adjust the position of the upper shaft box 6a, so that the spacing between the upper and lower dies 14a, 16b is determined according to the plate thickness of the material 1 to be shaped by reducing and forming in the direction of plate thickness.
Next, the motor is operated to rotate the upper and lower rotating shafts 7a, 7b, and the material 1 to be shaped is inserted between the upper and lower dies 14a, 14b, and the material 1 is reduced and formed by means of the upper and lower dies 14a, 14b that move towards and away from each other and with respect to the transfer line S while moving in the direction of the transfer line S as determined by the displacement of the eccentric portions of the rotating shafts 7a, 7b. 
At this time, appropriate hydraulic pressure is applied to the hydraulic chambers of the hydraulic cylinders 15a, 15b, and the angles of the die holders 13a, 13b are changed so that the forming surfaces 17a, 17b of the upper and lower dies 14a, 14b, on the downstream B side of the transfer line, are always parallel to the transfer line S.
However, the flying-sizing press machine shown in FIG. 3 has much larger contact areas between the forming surfaces 16a, 16b, 17a and 17b of the dies 14a, 14b and the material 1 to be formed, compared to the dies of a plate reduction press machine, and because the above-mentioned contact areas increase as the dies 14a, 14b approach the transfer line S, a large load must be applied to the dies 14a, 14b during reduction.
In addition, the die holders 13a, 13b, rods 9a, 9b, rotating shafts 7a, 7b, shaft boxes 6a, 6b, housing 4, etc. must be strong enough to withstand the reducing load applied to the dies 14a, 14b, so that these members are made larger in size.
Also, the flying-sizing press machine shown in FIG. 3 may suffer from the problem that the leading and trailing ends of the material 1 being reduced and formed are locally bent to the left or right, or with a camber so that when a long material 1 is being formed it generally warps, unless the centers of the reducing forces from the dies 14a, 14b on the material 1 to be shaped are in close alignment when the material 1 is reduced and formed by the upper and lower dies 14a, 14b. 
2. With a conventional rolling mill known in the prior art, in which a material is rolled between two work rolls, there is a reduction ratio limit of normally about 25% due to the nip angle limitation. Therefore, it is not possible to reduce the thickness of a material by a large ratio (for example, reducing a material from about 250 mm thickness to 30 to 60 mm) in a single pass, therefore three or four rolling mills are arranged in tandem in a tandem rolling system, or the material to be rolled is rolled backwards and forwards in a reverse rolling system. However, these systems are accompanied with practical problems such as the need for a long rolling line.
On the other hand the planetary mill, Sendzimir mill, cluster mill, etc. have been proposed as means of pressing that allow a large reduction in one pass. However, with these rolling mills, small rolls press the material to be rolled at a high rotational speed, resulting in a great impact, therefore the life of the bearings, etc., is so short that these mills are not suitable for mass production facilities.
On the other hand, various kinds of press apparatus modified from the conventional stentering press machines have been proposed (for example, Japanese patent No. 014139, 1990, unexamined Japanese patent publication Nos. 222651, 1986, 175011, 1990, etc.).
An example of the xe2x80x9cFlying-sizing press apparatusxe2x80x9d according to the unexamined Japanese patent publication No. 175011, 1990 is shown in FIG. 4; rotating shafts 22 are arranged in the upper and lower sides or the left and right sides of the transfer line Z of a material to be shaped, and the bosses of rods 23 with a required shape are connected to eccentric portions of the rotating shafts 22, and in addition, dies 24 arranged on opposite sides of the transfer line of the material to be shaped are connected to the tips of the rods 23; when the rotating shafts 22 are rotated, the rods 23 coupled to the eccentric portions of the rotating shafts cause the dies 24 to press both the upper and lower surfaces of the material 1 to be shaped, thereby the thickness of the material to be shaped is reduced.
However, the above-mentioned high-reduction means are associated with problems such as (1) a material to be reduced cannot be easily pressed by the flying-sizing apparatus in which the material is reduced as it is being transferred, (2) the means are complicated with many component parts, (3) many parts must slide under heavy loads, (4) the means are not suitable for heavily loaded frequent cycles of operation, etc.
With conventional high-reduction pressing means known in the prior art, the position of the dies is controlled to adjust the thickness of the material to be pressed by means of a screw, wedge, hydraulic cylinder, etc., and, as a result, there are the practical problems that the equipment is large, costly, complicated, and vibrates considerably.
3. Conventionally, a roughing-down mill is used to roll a slab. The slab to be rolled is as short as 5 m to 12 m, and the slab is rolled by a plurality of roughing-down mills or by reversing mills in which the slab is fed forwards and backwards as it is rolled. In addition, a reduction press machine is also used. Recently, because a long slab manufactured by a continuous casting system has been introduced, there is a demand for the continuous transfer of the slab to a subsequent pressing system. When a material is rough rolled using a roughing-down mill, the minimum nip angle (about 17xc2x0) must be satisfied, so the reduction limit xcex94t per pass is about 50 mm. Because the slab is continuous, reverse rolling is not applicable, so that to obtain the desired thickness, a plurality of roughing-down mills must be installed in series, or if a single rolling mill is to be employed, the diameter of the work rolls should be very large.
Consequently, a reduction press machine is used. FIG. 5 shows an example of such a machine in which the dies are pressed by sliders, to provide a flying-press machine that can press a moving slab. Dies 32 provided above and below the slab 1 are mounted on sliders 33, and the sliders 33 are moved up and down by the crank mechanisms 34. The dies 32, sliders 33 and crank mechanisms 34 are reciprocated in the direction of transferring the slab, by the feeding crank mechanisms 35. The slab 1 is conveyed by pinch rolls 36 and transfer tables 37. When the slab is being reduced, the dies 32, sliders 33 and crank mechanisms 34 are moved in the direction of transferring the slab by means of the feeding crank mechanisms 35, and the pinch rolls 36 transfer the slab 1 in synchronism with this transfer speed. A start-stop system can also be used; the slab 1 is stopped when the system is working as a reduction press machine and the slab is reduced, and after completing reduction, the slab is transferred by a length equal to a pressing length, and then pressing is repeated.
There are problems in the design and manufacturing cost of the aforementioned roughing-down mill with large diameter rolls, and the use of rolls with a large diameter results in a shorter life for the rolls because of the low rolling speed and difficulty in cooling the rolls. With the reduction press machine using sliders and feeding crank mechanisms shown in FIG. 5, the cost of the equipment is high because the mechanisms for reciprocating the sliders, etc., in the direction of movement of a slab are complicated and large in scale. In addition, the sliders vibrate significantly in the vertical direction. With a reduction press machine using a start-stop system, the slab must be accelerated and decelerated repeatedly from standstill to transfer speed, and vice versa. The slab is transferred using pinch rolls and transfer tables, and these apparatus become large due to the high acceleration and deceleration.
4. When a material is reduced by a large amount, according to the prior art, long dies were used to reduce the material while it was fed through the dies by the length thereof during one or several pressings. Defining the longitudinal and lateral directions as the direction in which the pressed material is moved and the direction perpendicular to the longitudinal direction, respectively, the material to be pressed by a large amount in the longitudinal direction is pressed by dies that are long in the longitudinal direction using single pressing or by means of a plurality of pressing operations while feeding the material to be pressed in the longitudinal direction. FIG. 6 shows an example of the above-mentioned reduction press machine, and FIG. 7 illustrates its operation. The reduction press is equipped with (lies 42 above and below a material 1 to be pressed, hydraulic cylinders 43 for pressing down the dies 42, and a frame 44 that supports the hydraulic cylinders 43. A pressing operation is described using the symbols L for the length of the dies 42, T for the original thickness of the material 1 to be pressed, and t for the thickness of the material after pressing. FIG. 7(A) shows the state of the dies 42 set to a location with thickness T on a portion of material to be pressed next, adjacent to a portion with thickness t which has been pressed. (B) shows the state in which the dies have pressed down from the state (A). (C) is the state in which the dies 42 have been separated from the material 1 being pressed, that has then been moved longitudinally by the pressing length L, and completely prepared for the next pressing, which is the same state as (A). Operations (A) to (C) are repeated until all the material is reduced to the required thickness.
The longer the dies, the greater the force that is required for reduction, so the reduction press machine must be large. With a press machine, pressing is usually repeated at high speed. When an apparatus with a large mass is reciprocated at a high speed, a large power is required to accelerate and decelerate the apparatus, therefore the ratio of the power required for acceleration and deceleration to the power needed for reducing the material to be pressed is so large that much power is spent on driving the apparatus. When the material is reduced, the volume corresponding to the thinned portion must be displaced longitudinally or laterally because the volumes of the material before and after reduction are substantially the same. If the dies are long, the material is constrained so that it is displaced longitudinally (this phenomenon is called material flow), so that pressing becomes difficult especially when the reduction is large.
When a material to be rolled is reduced conventionally in a horizontal mill, the gap between the rolls of the horizontal mill is set so that the rolls are capable of gripping the material to be rolled considering the thickness of the material after forming, therefore the reduction in thickness allowed for a single pass is limited so that when a large reduction in the thickness is required, a plurality of horizontal mills have to be installed in series, or the material must be moved backwards and forwards through a horizontal mill while the thickness is gradually reduced, according to the prior art. Another system was also proposed in the unexamined Japanese patent publication No. 175011, 1990; eccentric portions are provided in rotating shafts, the motion of the eccentric portions is changed to an up/down movement using rods, and a material to be pressed is reduced continuously by these up/down movements.
The system with a plurality of horizontal mills arranged in tandem (series) has the problems that the equipment is large and the cost is high. The system of passing a material to be pressed backwards and forwards through a horizontal mill has the problems that the operations are complicated and a long rolling time is required. The system disclosed in the unexamined Japanese patent application No. 175011, 1990 has the difficulty that large equipment must be used, because a fairly large rotating torque must be applied to the rotating shafts to produce the required reducing force as the movement of the eccentric portions of the rotating shafts has to be changed to an up/down motion to produce the necessary reducing force.
5. Conventionally, a roughing-down mill is used to press a slab. The slab to be pressed is as short as 5 to 12 m, and to obtain the specified thickness, a plurality of roughing-down mills are provided, or the slab is moved backwards and forwards as it is pressed in the reversing rolling method. Other systems also used practically include a flying press machine that transfers a slab while it is being pressed, and a start-stop reduction press machine which stops conveying the material as it is being pressed and transfers the material during a time when it is not being pressed.
Since long slabs are produced by continuous casting equipment, there is a practical demand for a slab to be conveyed continuously to a subsequent press apparatus. When a slab is rough rolled in a roughing-down mill, there is a nip angle limitation (about 17xc2x0), so the reduction per rolling cannot be made so large. Because the slab is continuous, it cannot be rolled by reverse rolling, therefore to obtain the preferred thickness, a plurality of roughing-down mills must be installed in series, or if a single mill is involved, the diameter of the work rolls must be made very large. There are difficulties, in terms of design and cost, in manufacturing such a roughing-down mill with large-diameter rolls, and large diameter rolls must be operated at a low speed when rolling a slab, so the rolls cannot be easily cooled, and the life of the rolls becomes shorter. Because a flying press can provide a large reduction in thickness and is capable of reducing a material while it is being conveyed, the press can continuously transfer the material being pressed to a downstream rolling mill. However, it has been difficult to adjust the speed of the material to be pressed so that the flying press and the downstream rolling mill can operate simultaneously to reduce and roll the material. In addition, it has not been possible to arrange a start-stop reduction press machine and a rolling mill in tandem to reduce a slab continuously; with the start-stop reduction press, the material being pressed is stopped during pressing, and is transferred when it is not being pressed.
Another system in practical use is the flying system in which the sliders that press down on a slab are moved up and down in synchronism with the transfer speed of the slab.
In the start-stop system, the heavy slab is accelerated and decelerated every cycle from standstill to the maximum speed Vmax, and accordingly the capacity of the transfer facilities such as the pinch rolls and transfer tables must be large. Because of the discontinuous operation, it is difficult to carry out further operations on a downstream press machine. The flying system requires a large capacity apparatus to produce the swinging motion, and to accelerate and decelerate the heavy sliders according to the speed of the slab. Another problem with this system is that this large capacity apparatus for producing the swinging motion causes considerable vibrations in the press machine.
Still another problem with this system is that if the speed of the slab deviates from that of the sliders, flaws may be produced in the slab or the equipment may be damaged.
Recently, a high-reduction press machine that can reduce a thick slab (material to be pressed) to nearly ⅓ of its original thickness in a single reduction operation, has been developed. FIG. 8 shows an example of a reduction press machine used for hot pressing. With this reduction press machine, dies 52a, 52b are disposed opposite each other vertically on opposite sides of the transfer line S, and are simultaneously moved towards and away from a material 1 to be pressed that travels on the transfer line S by the reciprocating apparatus 53a, 53b incorporating eccentric axes, rods, and hydraulic cylinders, so that material of a thickness of, for example, 250 mm can be reduced to 90 mm by a single reducing operation.
However, the reduction of the aforementioned high-reduction press machine can be as large as 160 mm, that is, the reduction on one side is as large as 80 mm. According to the prior art, there is a small difference of thickness before and after pressing, so the transfer levels of the transfer devices of a press machine on the inlet and outlet sides are substantially the same. With the above-mentioned high-reduction press machine, however, there is the problem that the material 1 to be pressed is bent if the transfer levels are identical. Another problem of the machine is that the transfer device is overloaded.
1. The present invention has been accomplished under the circumstances mentioned above, and the first object of the present invention is to provide a plate reduction press apparatus and methods that can efficiently reduce a material to be shaped in the direction of the thickness of the plate, can securely transfer the material to be shaped, can decrease the load imposed on the dies during reduction, and can prevent bending of the material to be shaped to the left or right as a result of the reducing and forming operations.
To achieve the aforementioned first object of the present invention, in the plate reduction pressing method of the present invention, dies with convex forming surfaces protruding towards the transfer line are moved towards the transfer line from above and below the material to be shaped, when viewed from the side of the transfer line, in synchronism with the movement of the material to be shaped, in such a manner that a portion of the forming surfaces of the material is moved from the upstream side to the downstream side of the transfer line and the material to be shaped is reduced in the direction of the plate thickness.
The plate thickness reduction press apparatus of another embodiment of the present invention, is provided with die holders arranged opposite each other above and below a transfer line in which a material to be shaped is moved horizontally, dies mounted on the above-mentioned die holders and comprised of convex forming surfaces protruding towards the transfer line when viewed from the side of the transfer line, upstream eccentric shafts arranged for each die holder on the opposite side from the transfer line and extending in the direction lateral to the transfer line, downstream eccentric shafts arranged for each die holder on the opposite side from the transfer line in alignment with the aforementioned upstream eccentric shafts, in the downstream direction of the transfer line, and comprised of eccentric portions with a different phase angle from the phase angle of the eccentric portions of the upstream eccentric shafts, upstream rods whose tips are connected to portions of the die holders, close to the ends on the upstream side of the transfer line through bearings and the other ends of which are connected to the eccentric portions of the upstream eccentric shafts through bearings, downstream rods whose tips are connected to portions of the die holders, close to the ends on the downstream side of the transfer line through bearings and the other ends of which are connected to the eccentric portions of the downstream eccentric shafts through bearings, and mechanisms for moving the dies backwards and forwards that reciprocate the above-mentioned die holders relative to the direction of the transfer line.
According to the plate reduction press apparatus of another embodiment of the present invention, the mechanisms for moving the dies backwards and forwards in the plate press apparatus are provided with arms one end of each of which is fixed to the die holder, and guide members which are installed near the die holders and guide the other end of each of the arms.
In the plate reduction press apparatus according to the invention, the mechanisms for moving the dies backwards and forwards are provided with actuators one end of each of which is connected to one of the die holders through a first bearing and the other end of each thereof is connected to a predetermined fixing member through a second bearing.
The plate reduction press apparatus of another embodiment of the present invention is composed of the mechanisms for moving the dies backwards and forwards in the plate reduction press apparatus, comprised of eccentric shafts for backwards and forwards movements, provided near the die holders and rods for backwards and forwards movements, one end of each of the aforementioned rods being connected to one of the die holders through a first bearing and the other end thereof being connected to one of the eccentric portions of the eccentric shafts for backwards and forwards movements.
In the plate reduction press apparatus of a still further embodiment of the invention, the mechanisms for moving the dies backwards and forwards in the plate reduction press apparatus of the present invention are composed of levers one end of each of which is connected to one of the die holders through a first bearing and the other end thereof is connected to a predetermined fixing member through a second bearing.
According to the plate reduction pressing method of the present invention, dies with convex forming surfaces protruding towards the transfer line are moved towards the transfer line from above and below the material to be shaped in synchronism with the movement of the material to be shaped, and given a swinging motion such that the portions of the forming surfaces in contact with the material to be shaped move from the downstream side of the transfer line to the upstream side thereof, thereby the areas of the material being shaped, in contact with the forming surfaces, are made small to reduce the pressing load on the dies.
In any of the plate reduction press apparatus according to the present invention, the die holders on which the dies are mounted are given a swinging motion by the upstream eccentric shafts, downstream eccentric shafts, upstream rods and downstream rods in such a manner that the portions of the forming surfaces of the dies, in contact with the material to be shaped, are shifted from the downstream side to the upstream side of the transfer line, while moving the dies towards the transfer line, thereby the areas of the forming surfaces in contact with the material to be shaped are made small to reduce the load applied to the dies during pressing.
Also, when the forming surfaces of the dies are in contact with the material to be shaped, the mechanisms for moving the dies backwards and forwards move the die holders towards the downstream side of the transfer line, and convey the material being reduced and formed without any material being displaced backwards, towards the downstream side of the transfer line.
To achieve the above-mentioned first object of the present invention, the plate reduction press apparatus according to one embodiment of the invention is provided with dies arranged vertically opposite each other on opposite sides of a transfer line in which a material to be shaped is transferred horizontally, and moving towards and away from the transfer line in synchronism with each other, a plurality of upstream table rollers arranged on the upstream side of the dies on the transfer line in such a manner that the lower surface of the material to be shaped, which is to be inserted between the dies, can be supported substantially horizontally, a plurality of downstream up and down table rollers arranged on the downstream side of the dies on the transfer line in such a manner that the downstream up and down table rollers can be raised and lowered and can support the lower surface of the material being shaped and fed out of the dies, and a plurality of downstream table rollers arranged on the downstream side of the downstream up and down table rollers on the transfer line in such a manner that the lower surface of the material being shaped and fed out of the dies can be supported substantially horizontally at a height substantially the same as the height of the aforementioned upstream table rollers.
The plate reduction press apparatus according to a further embodiment of the invention is provided with dies arranged vertically opposite each other on opposite sides of a transfer line in which a material to be shaped is transferred horizontally, and moving towards and away from the transfer line in synchronism with each other, a plurality of upstream up and down table rollers on the upstream side of the dies on the transfer line in such a manner that the upstream up and down table rollers can be raised and lowered, and the lower surface of the material to be shaped, which is to be inserted between the dies, can be supported and a plurality of downstream table rollers arranged on the downstream side of the dies on the transfer line in such a manner that the lower surface of the material being shaped and fed out of the dies can be supported.
The plate reduction press apparatus according to yet another embodiment of the present invention is comprised of dies arranged vertically opposite each other on opposite sides of a transfer line in which a material to be shaped is transferred horizontally, and moving towards and away from the transfer line in synchronism with each other, a plurality of upstream up and down table rollers on the upstream side of the dies on the transfer line in such a manner that the upstream up and down table rollers can be raised and lowered, and the lower surface of the material to be shaped, which is to be inserted between the dies, can be supported, and a plurality of downstream up and down table rollers arranged on the downstream side of the dies in such a manner that the lower surface of the material being shaped and fed out of the dies can be supported.
According to the method of operating the plate reduction press apparatus according to one embodiment of the invention, when a long material to be shaped is inserted, reduced and formed in the direction of plate thickness between both dies, the vertical positions of the downstream up and down table rollers near the dies are determined in such a manner that the material being shaped and fed out of the dies is substantially horizontal, and the vertical positions of the downstream up and down table rollers on the side farther from the dies are determined in such a manner that the material being shaped gradually descends towards the downstream table rollers.
In the method of operating the plate reduction press apparatus according to one embodiment, when a long material to be shaped is inserted, reduced and formed in the direction of the plate thickness between both dies, the vertical positions of the upstream up and down table rollers near the dies are determined in such a manner that the material to be shaped, which is to be inserted between the dies, is substantially horizontal.
According to a further embodiment of the present invention for operating the plate reduction press apparatus, when a long material to be shaped is inserted, reduced and formed in the direction of the plate thickness between both dies, the vertical positions of the upstream up and down table rollers near the dies and the downstream up and down table rollers are determined in such a manner that the material to be shaped, which is to be inserted between the dies, and the material being shaped and fed out of the dies are substantially horizontal.
In the method according to a further embodiment of the present invention for operating the plate reduction press apparatus of the invention, the positions of the upper surfaces of the downstream up and down table rollers are determined to be identical to the positions of the upper surfaces of the upstream table rollers and the downstream table rollers, when no long material to be shaped is inserted, or being reduced or formed in the direction of the plate thickness between both dies.
When using the plate reduction press apparatus of the present invention according to the method of another embodiment of the invention, the positions of the upper surfaces of the upstream up and down table rollers are determined to be identical to the positions of the upper surfaces of the downstream table rollers, when no long material to be shaped is inserted, or being reduced or formed in the direction of the plate thickness between both dies.
In the method for operating the plate reduction press apparatus according to one embodiment of the present invention, when no long material to be shaped is inserted, or being reduced or formed in the direction of the plate thickness between both dies, the positions of the upper surfaces of the upstream up and down table rollers and the downstream table rollers are determined to be identical to each other.
With the plate reduction press apparatus of one embodiment of the present invention, the vertical positions of the downstream up and down table rollers located on the transfer line downstream of the dies are adjusted according to the amount of the reduction in the direction of the plate thickness of the material being shaped by the dies, and the lower surface of the material being shaped and fed out from the dies is maintained in the most suitable state.
In the plate reduction press apparatus of another embodiment of the present invention, the vertical positions of the upstream up and down table rollers located on the transfer line upstream of the dies are adjusted according to the amount of the reduction in the direction of the plate thickness of the material to be shaped, and the lower surface of the material to be inserted between the dies and shaped is maintained in the most suitable state.
In the plate reduction press apparatus according to one embodiment of the present invention, the vertical positions of the upstream up and down table rollers located on the transfer line upstream of the dies and the downstream up and down table rollers located on the transfer line downstream of the dies are adjusted according to the amount of the reduction in the direction of the plate thickness of the material being formed by the dies, and the lower surface of the material being shaped and fed out from between the dies is maintained in the most suitable state.
When using the plate reduction press apparatus of the invention according to the method of one embodiment, the vertical positions of the downstream up and down table rollers on the portion of the transfer line near to the press machine are determined in such a manner that the material being reduced, shaped and fed out from between the dies is substantially horizontal, and the vertical positions of the downstream up and down table rollers farther down the transfer line are determined in such a manner that the material being shaped and fed out of the aforementioned downstream up and down table rollers gradually descends towards the downstream table rollers, and the portion of the material being reduced and shaped is moved smoothly.
According to the method of one embodiment of the present invention for operating the plate reduction press apparatus of the invention, the vertical positions of the upstream up and down table rollers near the dies are determined in such a manner that a long material to be shaped, which is to be inserted between the dies, is substantially horizontal, when the long material to be shaped is inserted, reduced and formed in the direction of the plate thickness between both dies, the portion of the material to be reduced and shaped is moved smoothly.
When the plate reduction press apparatus of the present invention is operated according to the method of one embodiment of the invention, the vertical positions of the upstream up and down table rollers and the downstream up and down table rollers are determined in such a manner that the material being reduced, shaped and fed out from between the dies is substantially horizontal, and the portion of the material to be reduced and shaped and the portion of the material being reduced and shaped are moved smoothly.
According to the method of the present invention for operating the high-reduction press apparatus of the invention, the vertical positions of the downstream up and down table rollers are determined to correspond with the positions of the upstream table rollers and the downstream table rollers, and material passed between the dies without being reduced and shaped is moved smoothly.
When the plate reduction press apparatus of the present invention is operated by the method of a further embodiment, the positions of the upper surfaces of the upstream up and down table rollers are determined to be identical to the positions of the upper surfaces of the downstream table rollers, and material passed between the dies without being reduced and formed is moved smoothly.
In the method of the present invention for operating the high-reduction press apparatus according to one embodiment of the invention, the vertical positions of the upstream up and down table rollers and the downstream up and down table rollers are determined to be the same as each other, and material passed between the dies without being reduced and shaped is moved smoothly.
Furthermore, according to the plate reduction pressing method according to one embodiment of the present invention for achieving the aforementioned first object of the invention, a first reduction in plate thickness is performed; in this sub-method the material to be shaped is transferred from the upstream side of the transfer line to the downstream side of the transfer line, upstream dies with forming surfaces facing the above-mentioned material to be shaped are moved towards the material to be shaped as the upstream dies are moved in the downstream direction of the transfer line and the upstream dies are moved away from the material to be shaped as the upstream dies are moved in the upstream direction of the transfer line, in synchronism with each other, and the aforementioned material to be shaped is reduced and shaped in the direction of the plate thickness sequentially, and then the second reduction in plate thickness is carried out; in this sub-method, downstream dies with forming surfaces facing the above-mentioned material to be shaped are moved towards the material being shaped in the opposite phase to the phase of the upstream dies while the downstream dies are moved in the downstream direction of the transfer line from above and below a portion of the material, whose thickness has been reduced by the first plate thickness reduction sub-method, and the downstream dies are moved away from the material being shaped as the downstream dies are moved in the upstream direction of the transfer line, in synchronism with each other, and the material which has been shaped by the first plate reduction is further reduced and shaped in the direction of the plate thickness sequentially.
With the plate reduction press apparatus according to a further embodiment of the present invention, upstream sliders are arranged vertically opposite each other on opposite sides of a transfer line; in which a material to be shaped is transferred, mechanisms for moving the upstream sliders move the above-mentioned upstream sliders towards the transfer line and move the upstream sliders away from the transfer line, upstream dies are mounted on the upstream sliders in such a manner that the upstream dies can move along the direction of the transfer line, and are comprised of forming surfaces facing the transfer line, mechanisms for moving the upstream dies move the above-mentioned upstream dies in a reciprocating manner in the direction of the transfer line, downstream sliders are located on the transfer line downstream of the upstream sliders, opposite each other on opposite sides of the transfer line, mechanisms for moving the downstream sliders move the downstream sliders towards the transfer line and move the downstream sliders away from the transfer line, downstream dies are mounted on the downstream sliders in such a manner that the downstream dies can move along the direction of the transfer line, and are comprised of forming surfaces facing the transfer line, and mechanisms for moving the downstream dies move the downstream dies in a reciprocating manner in the direction of the transfer line.
The plate reduction press apparatus according to a further embodiment of the present invention is provided with, in addition to the components of the plate reduction press apparatus of the invention, mechanisms for moving the upstream sliders comprised of upstream crank shafts arranged on the opposite side of the upstream sliders from the transfer line, and upstream rods one end of each of which is connected to an eccentric portion of one of the upstream crank shafts through a first bearing and the other end of each of which is connected to one of the upstream sliders through a second bearing, and mechanisms for moving the downstream slider comprised of downstream crank shafts arranged on the opposite side of the downstream sliders from the transfer line, and downstream rods one end of each of which is connected to an eccentric portion of one of the downstream crank shafts through a third bearing and the other end of each of which is connected to one of the downstream sliders through a fourth bearing.
Furthermore, the plate reduction press apparatus in one embodiment of the present invention is provided with, in addition to the component devices of the plate reduction press apparatus of the invention as described above, a synchronous drive mechanism that rotates the upstream crank shafts and the downstream crank shafts in synchronism in the same direction in such a manner that the eccentric portions of both of the upstream and downstream crank shafts maintain a phase difference of 180xc2x0.
Moreover, the plate reduction press apparatus of a further embodiment of the present invention is comprised of, in addition to the component devices of the plate reduction press apparatus of the invention, upstream crank shafts and downstream crank shafts supported by bearings in such a manner that both the above-mentioned crank shafts are substantially parallel to the direction orthogonal to the transfer line.
In the plate reduction pressing method according to one embodiment of the present invention, an unreduced and unformed portion of the material to be shaped is reduced and formed in the direction of its plate thickness by the upper and lower upstream dies, in the first plate thickness reduction sub-method, and then the portion of the material to be shaped, that has been reduced and formed, is further reduced and formed in the direction of its plate thickness by the upper and lower downstream dies, in the second plate thickness reduction sub-method, thereby the material to be shaped is reduced and shaped efficiently in the direction of its plate thickness.
In addition, the first and second plate thickness reduction sub-methods are operated alternately on an unreduced and unformed portion and a partially reduced portion of the material to be shaped, respectively, in order to reduce the loads applied to the upstream and downstream dies during reduction.
In any of the plate reduction press apparatus of the present invention, the mechanisms for moving the upstream sliders move the upstream dies towards the transfer line together with the upstream sliders, and an unreduced and unformed portion of the material to be shaped is reduced in the direction of its plate thickness by the upper and lower upstream dies, and then the mechanisms for moving the downstream sliders move the downstream sliders and downstream dies towards the transfer line, and the portion of the material to be shaped, already reduced by the upstream dies, is further reduced in the direction of its plate thickness by the upper and lower downstream dies, thus the material to be shaped is reduced and formed efficiently in the direction of its plate thickness.
In addition, the upstream and downstream dies are moved towards and away from the transfer line, in the opposite phase to each other, by means of the mechanisms for moving the upstream and downstream sliders, respectively, so that the loads applied to the upstream and downstream dies during reduction are made smaller.
According to the plate reduction press apparatus of one embodiment of the present invention, as invented to achieve the first object of the invention, a pair of dies are arranged opposite each other on opposite sides of a transfer line of a material to be shaped and moved toward and away from each other in synchronism with each other, upstream side guides are arranged in the close vicinity of the aforementioned dies in the upstream direction of the transfer line in such a manner that the upstream side guides are opposite each other in the lateral direction of the material to be shaped on opposite sides of the transfer line, and comprised of a first pair of side guide units that can move towards and away from the transfer line, and downstream side guides arranged in the close vicinity of the above-mentioned dies in the downstream direction of the transfer line in such a manner that the downstream side guides are opposite each other in the lateral direction of the material being shaped on opposite sides of the transfer line, and comprised of a second pair of side guide units that can move towards and away from the transfer line.
The plate reduction press apparatus of the present invention is provided with a pair of dies arranged opposite each other on opposite sides of a transfer line of a material to be shaped and moved towards and away from each other in synchronism with each other, upstream side guides arranged in the close vicinity of the aforementioned dies in the upstream direction of the transfer line in such a manner that the upstream side guides are opposite each other in the lateral direction of the material to be shaped on opposite sides of the transfer line, and comprised of a first pair of side units that can move towards and away from the transfer line, upstream vertical rollers supported by the corresponding upstream side guides in such a manner that the upstream vertical rollers can contact the lateral edges of the material to be shaped, when the material passes between the above-mentioned upstream side guides, downstream side guides arranged in the close vicinity of the aforementioned dies in the downstream direction of the transfer line in such a manner that the down stream side guides are opposite each other in the lateral direction of the material being shaped on opposite sides of the transfer line, and comprised of a second pair of side guide units that can move towards and away from the transfer line, and downstream vertical rollers supported by the corresponding downstream side guides in such a manner that the downstream vertical rollers can contact the lateral edges of the material being shaped, when the material passes between the downstream side guides.
In any of the plate reduction press apparatus according to one embodiment of the present invention, a material to be reduced and shaped is moved from the upstream side to the downstream side of the transfer line, guided into the upper and lower dies by the left and right side guide units of the upstream side guides, the material to be shaped, after being reduced and formed by the dies and fed out on the downstream side of the transfer line, is prevented from being deflected to the left or right, by the left and right side guide units of the downstream side guides.
With the plate reduction press apparatus according to one embodiment of the present invention, when the material to be shaped is guided into the dies by the left and right side guide units of the upstream side guides, the lateral edges of the material are guided by the upstream vertical rollers to protect the lateral edges of the material to be shaped from rubbing against the side guide units, and the lateral edges of the material to be shaped are restrained by the left and right side guide units of the downstream side guides to prevent the material to be shaped from being deflected to the left or right, and guided by the downstream vertical rollers to protect the lateral edges of the material to be shaped from rubbing against the side guide units.
2. The second object of the present invention is to provide a plate reduction press apparatus with (1) the capability of a flying press apparatus that can reduce a material to be pressed while it is being moved, (2) small number of component parts and a simple configuration, (3) a reduced number of portions that slide under load, (4) the capability for operating under a heavy load at a high operating rate, and (5) a simply constructed means of adjusting the positions of the dies and correcting the thickness of a material to be pressed.
The plate reduction press apparatus according to one embodiment of the present invention offers a plate reduction press apparatus provided with upper and lower drive shafts arranged opposite each other above and below a material to be pressed, and made to rotate, upper and lower press frames one end of each of which engages with one of the aforementioned drive shafts in a freely slidable manner, and the other ends of which are connected together in a freely rotatable manner, a horizontal guide device that supports the above-mentioned press frames at the point of connection in a manner that allows them to slide in the horizontal direction, and upper and lower dies mounted at the ends of the upper and lower press frames, opposite the material to be pressed, in which the upper and lower drive shafts are constructed as a pair of eccentric shafts that are located at both lateral ends and which have a phase difference relative to each other, and the upper and lower dies that are opened and closed with a rolling action by rotating the drive shafts, and the material to be pressed is transferred as the material is being pressed.
According to the configuration of the present invention as described above, when the drive shafts are rotated, the upper and lower dies move in a circular path, while rolling laterally at the same time, and are opened and closed by the pair of eccentric shafts of which the phase angles are shifted relative to each other. Consequently, the material to be pressed can be conveyed while being pressed, because the upper and lower dies move in the direction of the line while they are closing. In addition, because the upper and lower dies close with a rolling action, the load during pressing can be reduced. The amount of reduction is determined by the eccentricity of the eccentric shafts, so high-reduction pressing is possible without being limited by a nip angle, etc. Moreover, because the material to be pressed is conveyed while being reduced, the apparatus operates as a flying press.
In addition, only the eccentric shafts withstand loads during pressing, and the horizontal guide device is acted on by only a rather small load that only cancels the moments applied to the press frames, and furthermore, the moments applied to the upper and lower press frames cancel each other, so that the load imposed on the horizontal guide device is further reduced. Therefore, the construction can be simplified with a small number of component parts, and with a small number of portions that slide under load during pressing, and as a result, the apparatus can operate with high loads at a high operating frequency.
According to the plate reduction press apparatus according to a further embodiment of the present invention, a driving device to rotate and drive the drive shafts is provided, and the rotational speed of the driving device can be varied, and the rotational speed is determined in such a manner that the speed of moving the dies during reducing substantially matches the speed of feeding the material to be pressed.
With this configuration, the speed of the dies in the line direction can be made to be substantially equal to the speed of feeding the material to be pressed (a slab), so the load on the driving device that rotates and drives the drive shafts can be reduced.
The plate reduction press apparatus according to a further embodiment is provided with a looper device that creates a slack portion in the material to be pressed on the downstream side and holds up the material. In this configuration, the looper device can absorb deviations between the speed of the dies in the line direction and the speed of feeding the material to be pressed, so that the line speed can be synchronized with a finish rolling mill located further downstream.
The plate reduction press apparatus according to a further embodiment of the present invention provides a plate reduction press apparatus configured with upper and lower crank shafts arranged opposite each other above and below a material to be pressed and made to rotate, upper and lower press frames one end of each of which engages with one of the aforementioned crank shafts in a freely slidable manner, and the other ends of which are connected together in a freely rotatable manner, horizontal guide devices that support the above-mentioned press frames at the point of connection in a manner that allows them to move horizontally, and upper and lower dies mounted at the ends of the upper and lower press frames, opposite the material to be pressed; in which the crank shafts rotate to open and close the upper and lower dies, so transferring the material while pressing the material to be pressed, the material is transferred.
According to the above configuration based on the present invention, the upper and lower dies move in a circular path when the crank shafts rotate, and open and close. Consequently, as the upper and lower dies move in the direction of the line while closing, the material to be pressed can be conveyed while being reduced. The amount of reduction is determined by the eccentricity of the crank shafts, therefore high-reduction pressing is possible without being limited by a nip angle, etc. Also, the apparatus operates as a flying press because the material to be pressed is transferred while being reduced.
In addition, only the crank shafts withstand loads during pressing, and because the horizontal guide devices are acted on by only relatively small loads that are sufficient to only cancel the moments acting on the press frames, and also because the moments applied to the upper and lower press frames cancel each other, the loads on the horizontal guide devices become still smaller. As a result, the construction of the apparatus is made simple with few component parts, and with a small number of components that slide under load during pressing, so that the apparatus can operate with large loads at a high operating frequency.
With the plate reduction press apparatus according to yet another embodiment of the present invention, a driving device for rotating and driving the crank shafts is provided, and the rotational speed of the driving device is variable and is determined in such a manner that the speed of the dies in the line direction during pressing substantially matches the speed of feeding the material to be pressed.
With this configuration mentioned above, the speed of the dies in the line direction can be made to be substantially the same as the speed of feeding the material to be pressed (a slab), so the load on the driving device that rotates and drives the crank shafts can be reduced.
The plate reduction press apparatus according to another embodiment is provided with a looper device that creates a slack portion in the material to be pressed on the downstream side and holds up the material. Using this configuration, the looper device can absorb differences between the speed of the dies in the line direction and the speed of feeding the material to be pressed, so that the speed of the line can be synchronized with that of a finish rolling mill located further downstream.
The plate reduction press apparatus according to another embodiment is provided with up and down height adjusting plates that are maintained between the dies and the press frames, and the plates adjust the heights of the dies. By replacing these height adjusting plates, the heights of the dies can be adjusted freely, so compared to a conventional screw mechanism, etc., the construction of the apparatus can be made tougher, simpler, and more compact than a conventional one, consequently, the apparatus vibrates less and fails less often than a conventional machine, so the apparatus according to the present invention can be maintained more easily whilst the cost is reduced.
According to a further embodiment of the present invention, a hot slab pressing method is provided in which the feeding speed of the material to be pressed is made variable, relative to the maximum speed of the dies in the line direction. According to a preferred embodiment of the present invention, the speed of feeding the material to be pressed is varied in such a manner that at the beginning of pressing, the speed is made greater than the aforementioned maximum speed, and is made smaller at the intermediate and final stages.
The plate reduction press apparatus according to another embodiment of the present invention is comprised of upper and lower eccentric drive shafts arranged opposite each other above and below a material to be pressed and made to rotate, upper and lower synchronous eccentric shafts that rotate around the axes of the above-mentioned eccentric drive shafts, upper and lower press frames one end of each of which engages with one of the synchronous eccentric shafts in a freely slidable manner, and the other ends of which are connected together in a freely rotatable manner, and upper and lower dies mounted at the ends of the upper and lower press frames, facing the material to be pressed; in which the upper and lower dies are opened and closed by rotating the upper and lower eccentric drive shafts, and when the material to be pressed is pressed by the dies, the synchronous eccentric shafts synchronize the speed of the press frames in the direction of the transfer line with the speed of the material to be pressed in the direction of the transfer line.
With the configuration mentioned above according to the present invention, when the drive shafts are rotated, the upper and lower eccentric shafts rotate around fixed axes, and due to the rotation of the eccentric shafts, the upper and lower dies move in circular paths while opening and closing. As a result, the upper and lower dies can convey the material to be pressed in the direction of the line while reducing the material, by synchronizing the speed of the press frames in the direction of the line with the speed of the material to be pressed by means of the synchronous eccentric shafts during pressing with the dies. In this way, the amount of the reduction is determined by the eccentricity of the eccentric shafts without any nip angle restriction, etc., so high-reduction pressing can be carried out.
In this apparatus, only the eccentric shafts (dual-eccentric shafts) that rotate around the axes of the fixed shafts withstand loads during pressing, and only rather small loads that merely cancel the moments acting on the press frames are applied to the connection portions, in addition, because the moments acting on the upper and lower press frames cancel each other, the loads are further reduced. Therefore, there are few component parts, the construction is simple, there are only a small number of sliding locations which are loaded during pressing, and the apparatus can operate with high loads at a high operating frequency.
3. The third object of the present invention is to offer a plate reduction press apparatus and methods by means of which a slab is transferred while the plate thickness is being reduced with a high reduction ratio, and for which the construction of the apparatus is rather simple and which can reduce the slab with little vibration, and for which the required length of the apparatus in the line direction can be reduced.
To achieve the aforementioned third object, one embodiment of the present invention presents a plate reduction press apparatus provided with crank shafts arranged above and below a material to be pressed, sliders which engage with the above-mentioned crank shafts in a freely slidable manner and are moved with an eccentric motion, dies mounted on the sliders facing the material to be pressed, and a driving device for driving and rotating the crank shafts, in which the aforementioned crank shafts are composed of eccentric shafts that engage with the sliders, and support shafts arranged on both sides of the eccentric shafts with shaft center lines offset from the shaft center lines of the eccentric shafts, and at least one of the support shafts is comprised of a counterweight with an eccentric center substantially in a direction at 180xc2x0, to the direction of eccentricity of the eccentric shafts.
The crank shafts engage directly with the sliders, and when the crank shafts rotate, the eccentric shafts are rotated eccentrically about the axes of the support shafts, so the sliders move up and down and reduce the material to be pressed, while also moving backwards and forwards in the direction of the flow of material to be pressed. Thus, the sliders and the dies also move in the direction of the flow of material to be pressed during pressing, therefore the mechanisms for feeding the material during pressing, shown in FIG. 8, are not required. Consequently, the apparatus operates as a flying press and has a small number of component parts and a simple construction. In addition, because the counterweight provided on the support shafts is offset in a direction substantially 180xc2x0 to the eccentricity of the eccentric shafts, the accelerations and decelerations acting on the sliders are canceled and the vibration of the apparatus is reduced.
The plate reduction press apparatus according to another embodiment of the present invention is comprised of upper and lower press frames one end of each of which engages with one of the crank shafts in a freely slidable manner and is rotated eccentrically, and the other ends of which are connected together in a freely rotatable manner, horizontal guide devices that restrain the press frames at the point where they are connected together in a manner such that they are free to move in the horizontal direction, dies mounted at the ends of the above-mentioned press frames facing the material to be pressed, and a driving device for driving and rotating the aforementioned crank shafts, in which the crank shafts are provided with eccentric shafts engaged with the above-mentioned ends of the press frames, and support shafts arranged on both sides of the eccentric shafts with shaft center lines eccentric to the shaft center lines of the eccentric shafts, and at least one of the support shafts is comprised of a counterweight with an eccentric center substantially in a direction at 180xc2x0, to the direction of eccentricity of the eccentric shafts.
In this configuration as mentioned above, the ends of the press frames move in a circular path as the crank shafts rotate, so the dies connected thereto move up and down and reduce the material to be pressed, while also moving backwards and forwards in the direction of the flow of the material to be pressed, consequently by selecting the direction of rotation of the crank shafts, the dies can be made to move in the direction of the flow of the material to be pressed during pressing, that is, a flying press operation can be achieved. The other ends of the upper and lower press frames are connected together in a freely rotatable manner, and are guided so that they can only move in the horizontal direction, therefore the reaction moment imposed on one end during pressing can be canceled by the one from the other end. The apparatus according to this embodiment also does not require the mechanisms for feeding the material during pressing, shown in FIG. 8. Consequently there are few components and the construction is simple. In addition, the support shafts are provided with a counterweight of set in a direction substantially at 180xc2x0 to the direction of eccentricity of the eccentric shafts, so that accelerations and decelerations produced at the two ends are canceled out and the vibration of the apparatus can be reduced.
According to a further embodiment of the invention, the aforementioned counterweight has a mass sufficient to store rotational energy and also works as a flywheel.
As the counterweight rotates on a support shaft, it can store rotational energy, and it functions as a flywheel by means of a sufficient mass provided in the counterweight.
According to a still further embodiment of the invention, the inertia force due to the eccentricity of the counterweight is determined so as to substantially cancel out the inertia forces from the sliders and the inertia forces of the ends of the press frames.
Using the configuration described above, the vibration of the reduction press apparatus can be greatly reduced.
According to a still further embodiment of the invention which is aimed at achieving the third object mentioned above, the apparatus is provided with dies arranged above and below a slab, and equipped with sliders for each of the dies to give the dies an up, down, backwards and forwards swinging motion and a driving device for driving the sliders, in which each of the sliders is composed of a main unit with a circular hole with its center line in the lateral direction of the slab, and a crank with a first axis that engages with the circular hole and a second shaft with a diameter smaller than the diameter of the first shaft with its center line offset from the axis of the first shaft, and the second shaft is rotated and driven by the driving device.
When the second shaft rotates, the first shaft operates as a crank about the center line of the second shaft, and the first shaft engages with the circular hole and, moves the main unit up and down, and backwards and forwards. Thereby, the sliders press the dies, and can move the dies in a forward direction during pressing, so that the slab is transferred forwards (in the direction of the flow of the slab) while being reduced, therefore a continuous pressing operation is enabled. The invention thus provides a large amount of reduction because the dies press the slab from both the upper and lower sides of the slab.
According to another embodiment of the invention, there are dies arranged above or below a slab, sliders for giving the dies an up and down and backwards and forwards swinging motion, a driving device for driving the sliders, and slab supporting members arranged opposite the dies above and below the slab, in which each of the sliders is comprised of a main unit with a circular hole with its axis in the lateral direction of the slab, a first shaft engaged with the circular hole, and a crank composed of a second shaft with a diameter smaller than the diameter of the first shaft and with its center line offset from the axis of the first shaft, and the second shaft is rotated and driven by the driving device.
The apparatus according to this embodiment is provided with dies either above or below the slab, and slab supporting members are arranged opposite the dies above or below the slab, to support the slab. Compared to the invention of the prior embodiment, the amount of the reduction is smaller, and there is friction between the slab and the support members when the slab being reduced moves forwards, but the construction is simpler, and the cost can be further reduced.
In the scope of the invention according to a still further embodiment, the circular holes and the cranks provided in the aforementioned sliders are arranged in pluralities in a row along the direction of flow of the slab, and one crank accepts the force due to the moment of the load, and the other cranks produce pressing forces in this configuration.
By arranging pluralities of circular holes and cranks in a row in the direction of flow of the slab (forwards), the dies can be maintained parallel to each other. In addition, the pressing loads can be distributed to several cranks, so the construction of each crank can be made simpler.
In the invention according to yet another embodiment, the circular holes and the cranks provided in the above-mentioned sliders are arranged in pluralities in a row, and one crank accepts the force due to the load moments, and the other cranks are configured to produce pressing forces.
With this configuration, one crank bears the forces due to the unbalanced moments of the loads, and the other cranks generate only pressing forces, so the overall efficiency of a press machine can be increased.
With the invention according to still a further embodiment, the slab is conveyed by pinch rolls or tables, and when the sliders press the slab, it is conveyed at the same speed as the speed of the sliders in the forward direction.
When the sliders press the slab, the slab is transferred at the same speed as the forward speed of the sliders, and at other times, the slab is conveyed at an appropriate speed, for example, a speed synchronized with that of a subsequent machine. In this way, the slab can be reduced most suitably and conveyed continuously.
In the invention according to another embodiment, the distance L in which the slab moves in a cycle of the pressing period plus the period with a normal transfer speed, is not longer than the length L1 of the dies in the direction of flow of the slab.
Because the distance L slab 1 moves per cycle is no longer than the length L1 of the dies in the direction of flow of the slab, the reduction length for the next cycle is slightly superimposed on the length reduced in the previous cycle. Thus, the reduction in thickness can be properly accomplished.
According to a further embodiment of the present invention, aimed at achieving the third object mentioned above, the plate reduction press apparatus is provided with a pair of dies arranged opposite each other above and below a slab, and a swinging device that gives each of the dies a swinging motion backwards and forwards, towards the slab, and eccentric shafts rotating in the above-mentioned circular holes, in which each of the aforementioned eccentric shafts is comprised of a first shaft rotating in a circular hole with center line A on the same axis as the circular hole, and driving a second shaft with a center line B offset from that of the first shaft by a difference c.
According to this configuration, the two eccentric shafts rotating in a pair of circular holes in the sliders are located at an inclined angle or perpendicular to the direction of feeding the slab, therefore compared to the case in which the eccentric shafts are installed parallel to the line direction, the required length of the apparatus in the direction of the line can be reduced. In particular, when the eccentric shafts are arranged at an inclined angle, the pressing forces acting on the two eccentric shafts can be shared equally, so that the length of the apparatus in the direction of the line can be reduced at the same time as giving equal loading to each eccentric shaft. When the eccentric shafts are installed perpendicular to the direction of feed of the slab, it is possible to load the inner eccentric shafts more than the outer ones, and to make the outer eccentric shafts smaller.
Another embodiment of the present invention provides a plate reduction pressing method using a pair of dies arranged opposite each other above and below a slab, and a swinging device that moves each of the dies towards the slab, in which the slab is synchronized with the feeding speed of the dies when the slab is being pressed by the dies, and during the non-pressing period when the slab is separated from the dies, the slab is fed at a constant speed corresponding to a predetermined cycle speed.
Using this method mentioned above, the slab can be conveyed according to the upstream and downstream slab transfer speeds, so the entire line can be operated continuously.
4. The fourth object of the present invention is to provide plate reduction press apparatus and methods that can press a slab at a high speed with a large reduction, using a small pressing force, small driving power, and a small configuration of the entire press facilities.
To achieve the fourth object given above, the invention discloses a plate reduction press apparatus in which the longitudinal direction is defined as the direction in which a material to be pressed moves after being pressed, and N dies each of which has the same length in the longitudinal direction are arranged with an interval of NL between each die, and press the material.
Instead of using dies with a length of NL in the longitudinal direction, N dies each with a length L are arranged in tandem, and the interval between each of the dies is made to be NL. After each of the dies has finished pressing a material to be pressed, the material is moved longitudinally by a length NL. In this way, the material to be pressed can be reduced continually in lengths equal to the length NL. When a press machine is reciprocated at a high speed, inertia forces are created, and the magnitude of these forces depends on the GD2 of the component members that are being reciprocated. The GD2 value of a reciprocating body is greater than the sum of the GD2 values of each segment if the body is divided into N segments. Accordingly, the apparatus can be operated at a higher speed by dividing the dies into segments, because the total inertia force is smaller. In addition, the driving power is reduced when the dies are divided.
With the invention according to another embodiment, the lateral direction is defined as the direction orthogonal to the aforementioned longitudinal direction, and the longitudinal length of the dies is less than the length of the dies in the lateral direction.
The volumes of a material to be pressed, before and after pressing, are substantially equal to each other, therefore the volume of a reduced portion is spread out both longitudinally and laterally. However, if dies are long in the longitudinal direction, the material cannot be displaced easily in the longitudinal direction, so pressing with a large reduction becomes difficult, however because the length of the dies in the longitudinal direction is smaller than the length thereof in the lateral direction, the material can also be displaced fairly easily in the longitudinal direction, so that pressing with a large reduction can be achieved, and also the driving power of the plate reduction press apparatus is reduced.
In the invention according to a still further embodiment, the N dies press a material to be pressed at the same time.
As N dies press simultaneously, the pressing time can be made short and high-speed pressing can be achieved.
With the invention according another embodiment, at least one of the dies presses at a different time from the time the other dies press.
The power for driving a plurality of dies can be reduced by separating the dies into several or a couple of groups and differentiating the pressing times.
According to the plate reduction pressing method according to one embodiment for achieving the aforementioned fourth object of the present invention, the number of press machines pressing a material to be pressed with a press length L in the direction of the flow of the material to be pressed is defined as K, the press machines are arranged with K=1 on the upstream side of the pressing line, and with K increasing sequentially to K=N on the downstream side when N press machines are arranged in tandem, the material to be pressed is pressed in sequence from K=N to K=1, then after the material to be pressed is fed by a length NL, that is, the total of the pressing lengths of all the press machines, the pressing sequence from K=N to K=1 is repeated. The pressing force of each press machine is reduced by shortening the length L of the material to be pressed by each press machine from K=1 to K=N, so that press facilities are made smaller.
According to a still further embodiment of the invention, the number of press machines pressing a material to be pressed with a press length L in the direction of the flow of the material to be pressed is defined as K, the press machines are arranged with K=1 on the upstream side of the pressing line, and with K increasing sequentially to K=N on the downstream side when N press machines are arranged in a tandem configuration, each press machine reduces the material by xcex94t, press machine K reduces the material by at from its thickness after being pressed by press machine Kxe2x88x921, and the material is pressed by repeatedly feeding the material by one press length L after pressing the material in sequence from press machine K=1 to press machine K=N.
Each press machine, K=1 to K=N, presses the same portion of a material to be pressed in turn, by an amount xcex94t each, that is, by a total of Nxcex94t, therefore a large amount of reduction can be obtained in total, although each press machine only exerts a small pressing force. Accordingly, the capacity of each press machine can be small, and the pressing facilities are reduced in size.
5. The fifth object of the present invention is to provide a plate reduction press apparatus and methods with which a reduction operation by a reduction press machine and a rolling operation by a downstream rolling mill can be carried out at the same time, the capacities of the device for transferring the material to be pressed and the device to provide a swinging motion during reduction are small, the apparatus can be easily operated in series with downstream equipment, and even if the moving speed of the dies becomes different from the moving speed of the conveyor device during a pressing operation, the equipment will not be damaged, the material being pressed will not be bent, nor will the conveyor device be overloaded.
To achieve the fifth object described above, the invention is provided with speed adjusting rolls arranged between a reduction press machine and a rolling mill with spaces provided to deflect the material to be pressed, metering instruments arranged near the aforementioned speed adjusting rolls or in the vicinity thereof, to measure the length of the material to be pressed which has passed, and a control apparatus for controlling the operations of the above-mentioned reduction press machine and adjusting both speed adjusting rolls according to the measurement of the length metering instrument.
The control apparatus controls the operations of both the speed adjusting rolls and the press machine so that the material to be pressed is deflected between the press machine and the rolling mill to absorb any speed difference between the press machine and the rolling mill when the material is passing between them, length metering instruments are provided at both ends of the deflection between the press machine and the rolling mill to determine the difference between lengths passed, and the difference between the lengths passed is absorbed by the deflection and maintained in a predetermined range. Thereby, the press machine can press the material simultaneously with the operation of the rolling mill. The press machine can be either a flying press machine or a start-stop press machine, as far as simultaneous operation is concerned.
According to another embodiment of the invention, the aforementioned control apparatus takes the difference in the measured lengths of material which has passed the two length metering instruments over a period of a multiple of pressing cycles of the press machine, adjusts the number of pressing cycles of the press machine or the transfer speed of the speed adjusting rolls, or a combination thereof, and controls the pressing operations in such a manner that the difference in the lengths passed is brought to 0.
The difference in the lengths of material passed over a period of a multiple of pressing cycles of the press machine is absorbed by the deflection, while the control apparatus makes an adjustment by increasing or decreasing the number of pressing cycles per unit time of the press machine, or increases or decreases the transfer speed of each speed adjusting roll, or a combination of both, in order to bring the difference in the lengths passed close to 0.
According to a further embodiment of the invention, a deflection metering instrument is provided to measure the deflection of the material to be pressed, between the above-mentioned speed adjusting rolls, and the aforementioned control apparatus controls the pressing operations according to measurements thereof in such a manner that the deflections remain within a predetermined range.
Using the configuration described above, the deflection is kept within a predetermined range, so the press machine and the rolling mill are protected from excessive forces that might otherwise be applied if the deflection became too small, and also the elongation of the material being pressed at a high temperature due to an excessive deflection, can be prevented from occurring.
The invention according to a further embodiment provides a conveyor apparatus for the material being pressed that can be raised and lowered and is arranged between the aforementioned speed adjusting rolls, in which the material to be pressed is conveyed substantially at the same level as the transfer level of the speed adjusting rolls, when the leading end or trailing end of the material to be pressed passes the conveyor apparatus.
At the section where the material to be pressed is given a deflection, the conveyor apparatus is provided that can be raised and lowered and is equipped with rolls for conveying the material being pressed, in which the rolls are lowered when a deflection has been formed, and when the leading end or trailing end of the material to be pressed passes the conveyor apparatus, the level of the conveyor rolls is made substantially the same as the transfer level of the speed adjusting rolls. In this way, the leading end or trailing end of the material to be pressed or being pressed can pass smoothly across the section used for the deflection.
The invention according to a still further embodiment is aimed at achieving the fifth object described above in the pressing method of a crank type press machine that presses a material to be transferred and pressed using upper and lower dies, in which the dies are moved at the same speed as the speed of the material to be pressed during the pressing period, and the speed of feeding the material to be pressed is adjusted during the period when there is no pressing taking place in such a manner that during one cycle, the material to be pressed is moved by a predetermined distance L.
The material to be transferred and pressed is pressed by dies from above and below the material, and during pressing, the material is transferred at the same speed as that of the dies, and when the material is not being pressed, the speed of the material is adjusted to move the material by a distance L for each cycle, so that the material to be pressed can be transferred at the same speed during each cycle. In addition, the variations in the transfer speed during a cycle are much less than those of a start-stop apparatus, and the vibration of the equipment is much less than that of a slider system.
The invention of another embodiment is provided with dies arranged above and below a material to be pressed, crank devices for pressing each of the dies, and transfer devices for transferring the material to be pressed, in which the transfer devices move the material to be pressed at the same speed as the dies when the crank devices are pressing the material to be pressed with the dies, and when the material to be pressed is not being pressed, the transfer devices adjust the speed of feeding the material to be pressed and move the material by a predetermined distance L during one cycle of the pressing operation, and the above-mentioned distance L is not greater than the length L0 which is the reduction length of the dies in the direction of flow of the material to be pressed.
The upper crank device presses the material to be pressed when the die is near its lowest point of travel, and the lower crank device presses the same when the die is in the vicinity of the highest point of travel. As long as the dies are pressing the material to be pressed, the transfer devices transfer the material to be pressed and being pressed at the same speed as that of the dies. The distance L in which the transfer devices move the material to be pressed during one cycle of the crank devices is less than the length L0 in which the dies press the material in the direction of transfer, so the material to be pressed is pressed sequentially by one length at a time. In this mode of operation, variations in the transfer speed of the material to be pressed are limited to a reasonable range, therefore large-capacity transfer devices are not required. Furthermore, with this configuration it is not necessary to give heavy sliders a swinging motion to match the speed of the material to be pressed, therefore, no high-capacity device is required for the swinging motion. In addition, as the material to be pressed is transferred substantially continuously, the apparatus can be integrated easily with a downstream rolling mill.
According to a still further embodiment of the invention, in the pressing method of a crank type press machine that presses a material to be pressed and transferred using dies on both sides in the lateral direction of the transfer line, during the pressing period, the material to be pressed is moved at the same speed as the speed of the dies, and during the period when it is not being pressed, the speed of feeding the material to be pressed is adjusted in such a manner that during one cycle the material to be pressed is moved by a predetermined distance L.
The material to be pressed and transferred is pressed by the dies from both sides in the lateral direction, and during pressing, the material to be pressed is transferred at the same speed as that of the dies, and when the press machine is not pressing, the speed of the material to be pressed is adjusted to move the material by a distance L per cycle, so that the material to be pressed can be transferred at the same speed during each cycle. In addition, the variations in the transfer speed during a cycle are much less than those of a start-stop system, and the vibration is also much less than that of a slider system.
The invention of one embodiment is configured with dies arranged on both sides in the lateral direction of a material to be pressed, crank devices that press each of the dies in the lateral direction, and transfer devices that transfer the material to be pressed, in which the transfer devices move the material to be pressed at the same speed as the speed of the dies when the crank devices are pressing the material to be pressed in the lateral direction through the dies, and when the material to be pressed is not being pressed, the speed of feeding the material to be pressed is adjusted, and the material to be pressed is moved by a predetermined distance L in one cycle of a pressing operation, and the above-mentioned distance L is not greater than the length L0 which is the reduction length of the dies in the direction of flow of the material to be pressed.
The invention of a further embodiment is a modification of the invention of a prior embodiment using the apparatus of a prior embodiment for lateral pressing; the crank devices on both sides in the lateral direction of the material to be pressed, press the material in the lateral direction, using the dies, when they are near the point of travel closest to the material. While the dies press the material to be pressed, the transfer devices transfer the material at the same speed as that of the dies. Because the distance La that the transfer devices move the material to be pressed in one cycle of the crank devices is less than the pressing length La0 of the dies in the direction of flow of the material, the material to be pressed is pressed sequentially by a length La during each cycle. These operations keep the variations in the transfer speed of the material to be pressed in the limits of a reasonable range, so that no large-capacity transfer devices are required. In addition, because the configuration is such that heavy sliders do not have to be given a swinging motion corresponding to the speed of the material to be pressed, no large-capacity swinging device is needed. Also, as the material to be pressed is transferred essentially continuously, the material can be easily passed on to a downstream rolling machine.
According to yet another embodiment of the invention, a looper that forms a loop in the material to be pressed and adjusts the length thereof is provided downstream of the transfer devices specified above.
The transfer speed of the material to be pressed varies during one cycle of the crank devices. Consequently, the looper is provided to enable the material to be smoothly passed on to a subsequent rolling mill etc.
To achieve the fifth object described above, the invention of a further embodiment relates to the pressing method of a crank type press machine that presses a material to be transferred with pinch rolls and pressed with upper and lower dies; during the pressing period, the pinch rolls rotate in such a manner that the peripheral speed of the pinch rolls is made equal to the combination of the horizontal speed of the dies and the elongation speed of the material to be pressed, added or subtracted, and transfer the material to be pressed, and when the press machine is not pressing, the speed of feeding the material to be pressed is adjusted in such a manner that during one cycle, the material to be pressed is moved by a predetermined distance L, and the pressure of the pinch rolls during the pressing period is made smaller than the pressure thereof during the non-pressing period.
The material to be pressed and transferred is pressed by the dies from above and below the material, and during the pressing period, the pinch rolls are rotated at the peripheral speed equal to the sum of the horizontal speed of the dies plus or minus the elongation speed of the material to be pressed, and transfer the material to be pressed, and when the apparatus is not pressing, the speed of the pinch rolls is adjusted to give a moving distance of L per cycle, so the material to be pressed can be transferred at an equal speed during each cycle. In addition, because the pressure of the pinch rolls is made smaller during pressing than during the non-pressing period, even if there is a deviation between the sum of the speeds and the transfer speed of the pinch rolls, flaws can be prevented from being produced in the material to be pressed. Furthermore, variations in the transfer speed during a cycle are significantly smaller than those of a start-stop system, and the vibration is much less than that of a slider system.
The plate reduction press apparatus of another embodiment is provided with dies arranged above and below a material to be pressed, crank devices that press each of the dies, and pinch rolls that transfer the material to be pressed, in which the pinch rolls rotate in such a manner that the peripheral speed of the pinch rolls is made equal to a combination of the horizontal speed of the dies plus or minus the elongation speed of the material to be pressed, and transfer the material to be pressed when the crank devices are pressing the material to be pressed through the dies, and when the press machine is not pressing, the speed of feeding the material to be pressed is adjusted in such a manner that during one cycle, the material to be pressed is moved by a predetermined distance L and the distance L is not greater than the reduction length L0 of the dies in the direction of flow of the material to be pressed, and the pressure of the pinch rolls is made smaller during pressing with the dies than the pressure during the non-pressing period.
The upper crank devices press the material to be pressed using the dies, near the lowest point of travel, and the lower crank devices press the material with the dies near to the uppermost point of travel. While the dies are pressing the material to be pressed, the pinch rolls rotate at the same peripheral speed as the combined speed of the speed of the dies plus or minus the elongation speed of the material to be pressed, so that the material to be pressed is transferred. Because the distance L by which the pinch rolls transfer the material to be pressed during one cycle of the crank devices is less than the pressing length L0 of the dies in the direction of flow, the material to be pressed is pressed sequentially in steps each of length L. In addition, because the pressure of the pinch rolls is made smaller during pressing than the pressure during the non-pressing period, the material is protected from the occurrence of flaws even if there is a deviation between the combination speed and the transfer speed of the pinch rolls. Variations in the transfer speed of the material to be pressed are kept within reasonable limits during these operations, so no large-capacity transfer apparatus is required. Also, the configuration does not require heavy sliders to be given a swinging motion in synchronism with the speed of the material to be pressed, therefore no large-capacity swinging apparatus is needed. Because the material to be pressed is transferred essentially continuously, the press apparatus can easily be used in tandem with a downstream rolling mill.
According to the invention of another embodiment, the pressure on the above-mentioned pinch rolls is made smaller for a predetermined time t before or after the press machine begins to press.
By reducing the pressure on the pinch rolls at a predetermined time t before the press machine begins to press, the pinching force of the pinching rolls on the material to be pressed decreases, therefore the dies can grip the material to be pressed more firmly. The time t is the time required for gripping. When the pressure of the pinch rolls is made smaller at a predetermined time t after the beginning of pressing, it is intended to make sure the dies are capable of gripping the material to be pressed more firmly.
In the invention of a further embodiment, the pressure of the above-mentioned pinch rolls is made smaller when the pressing load becomes more than a predetermined value.
The pinch rolls press the material to be pressed with a high pressure until the pressing load of the press machine becomes more than a predetermined value, to securely feed the material to be pressed into the press machine, and thereafter the pressure is reduced.
The invention of a still further embodiment, aimed at achieving the fifth object mentioned above is comprised of inlet transfer devices that are arranged on the upstream side of a press machine, to transfer a material to be pressed, and can be raised and lowered, and outlet transfer devices that are arranged on the downstream side of the press machine, and transfer the material being pressed, and can be raised and lowered, in which the aforementioned inlet transfer devices are adjusted to give a height of transfer according to information which has been input concerning the thickness of the material to be pressed, in such a manner that the center line of the thickness of the material to be pressed is the same as the center line of the press machine, and the above-mentioned outlet transfer devices are adjusted for a height of transferring according to information about the thickness of the material after being pressed, in such a manner that the center line of the thickness of the material is the same as the center line of the press machine.
With a press machine in which a material to be pressed is transferred and pressed by dies from above and below the material, the press is designed so that a line midway between the dies is at a predetermined height, and the line passing through this height is called the press center line. The thickness of a material to be pressed has been measured during a process on the upstream side of the transfer line, when the material is delivered to the press machine. The height of transfer from the inlet transfer devices is determined so that the center of the thickness of the material coincides with the press center line. In addition, the thickness of the material after being pressed by the press machine is known from the design value of the press or by measurement, so the height of transfer of the outlet transfer devices is determined so that the center of the thickness of the material after being pressed matches the press center line. Consequently, the material being pressed is not bent after pressing, and also the outlet transfer devices will not be damaged.
In another embodiment of the invention, inlet transfer devices are provided that are arranged on the upstream side of a press machine for pressing a material to be pressed between upper and lower dies, that transfer the material to be pressed, and can be raised and lowered, and outlet transfer devices that are arranged on the downstream side of the aforementioned press machine, transfer the material being pressed, and can be raised and lowered, in which when the material to be pressed is passed through the press machine without being pressed with the upper and lower dies open, the transfer heights of the above-mentioned inlet transfer devices and the aforementioned outlet transfer devices are determined to be identical to each other and higher than the upper surface of the opened lower die.
In practice, a material to be pressed must sometimes be passed through a press machine without pressing, or a material which has been pressed unsuccessfully must be transferred in the reverse direction. In such cases, the upper and lower dies are opened, the transfer heights of the inlet transfer devices and the outlet transfer devices are made identical to each other and higher than the upper surface of the opened lower die, then the material to be pressed or which has been pressed can be passed either forwards or backwards.
According to a still further embodiment of the invention, the transfer method concerns the transfer devices that are arranged on the upstream and downstream sides of a press machine and can adjust the transfer height of a material to be pressed, in which both transfer devices can transfer the material to be pressed or after being pressed while the transfer devices maintain the height of the center of the thickness of the material to be pressed, unchanged during pressing.
The transfer devices arranged on the upstream and downstream sides of the press machine do not cause bending or otherwise adversely affect the material to be pressed and avoid unnecessary loads being imposed on the transfer devices, by adjusting the height of the center of the thickness of the material being pressed so that the height of the center of the thickness of the material is kept at the same level during transfer and pressing.
According to another embodiment of the invention, the transfer method concerns the transfer devices that are arranged on the upstream and downstream sides of a press machine and can adjust the transfer height of a material to be pressed, in which when the press dies are opened vertically in such a manner that the material to be pressed does not contact the dies when the material to be pressed is passed through the press machine, both transfer devices transfer the material to be pressed at the same height.
In practice, a material to be pressed must sometimes be passed through a press machine without pressing, or a material which has been pressed unsuccessfully must be transferred in the reverse direction. At this time, the press dies are opened upwards and downwards so that they do not touch the material to be pressed, and the material to be pressed is transferred with both transfer devices maintained at the same height.
The other objects and advantages of the present invention will be revealed as follows by referring to the attached drawings.